Highway-crossing signal



C. H. ZIERDT HIGHWAY CROSSING SIGNAL Jan. 6,1931.

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SYLVANIA PENnsYLvanIA, A

Y rarsnrorrlcs f- OF BOSEDALE; PENNSYLVANIA, ASSIGNOR T0 THE UNION SWITCH GORPGBATION 0F PENN- HIGHWAY-CROSSING SIGNAL H Application filed. August 22,

invention relates to highway crossing signals, that is, signals located at intersections of railways and highways, for warning oi the highway. when a train is approaching the crossing along the railway.

T will describe one form outhighwaycrossing signal embodying my invention, and will then point out the novel features thereof in claims.

In the accompany top plan View highway and highway crossing si vention. Fig. 2 1s a Similar reference lar parts in both views.

Referring to the characters 1 and 1 designate and also embodyi l. mg drawing, Fig. 1 is a showing the intersection of a a railway provided wlth a gn'al embodying my insectional view, show ng the apparatus illustrated in ng my invention.

characters rel'erto simithe reference drawing,

the track rails of a stretch of railway track, which rails are supported by theus'ual cross ties A.

stretch of railway tr indicated diagrammatically at H.

Located adj acent may and the highway is a:

signal comprising sound producing devi This ack intersects a highway the crossing of the railhighway crossing an elcctro-responsive ce, here shown-as a loud speaker D ot the usual and well known form.

The loud speaker secondary (S of 5 of which is const g'y from a battery 4t The device B is lo a transformer antly supplied with ener- D is connected with the T, the primary through a device cated in thetrackway at a point some distance from the highway H,

and as best seen rail 1 by means of to the flange of the 1 and bolts F and F structed in such ina rice vibrated, the

primary of transformer to the vibrations the form here shown, the

S non so;

a microphone havin J containing two spa G The space bctw in Fig. 2, is attached to the a bar C,

which is secured ail by clamps E and E 3, The device B is conuner that, when the dccurrent supnlicd to the T is varied in re-' of the oevice. In device B comprises an insulatinghousing ced carbon blocks G and een the blocks G and G is tilled with loose carbon granules K. The

device B is connecte primary 5 of trans d in the circuit with the former T by means of 1928; Serial 1e. 301,214.

wires 2 and 3, which wires are connected with. the carbon blocks G'and G respectively. .1

The operation of the "apparatus is as follows: When a train, approaching'highway H in the directionfindicated byithe arrow, is passing device B, the vibration of the track "ail 1* caused by the train, is transmitted to device B by means of timber C, and device B is continuously vibrated until the train has passed. beyond device B for. some distance. While device is'being vibrated, the carbon granules Kwithin the device are continually agitated, and the reristance of the path be tween carbon blocks Gr and G or device B is continuously varying, so that primary 5 of transformer T is supplied with a continuously varying current. This varying currentin primary 5 of transformer T'induces a vary ing electromotive force in secondary 6 of transformerv T, and the resultant current which then flows in loud speaker the speaker, thereby warning users of the highwayuo'r the approach of a train along the railwayi V It is a well knownfact that a microphone of the type described varies its resistance,

and therefore the current in the circuit in' in direct proportion to the intensity of the vibrations which are transmitted to the microphone. It is also a well known fact that a loud speaker is capable of converting variations in current into sound waves which correspond to the vibrations which produced. the variations in current. Since loud speaker D is supplied with current which varies in response to the variations in the resistance offdevice B, and since the resistance' of device B is varied in response to vibrations produced by a train in the vicinity of the device, it will be apparent that loud speaker D produces sound waves which are a reproduction of the sound waves caused by the train which is approaching highway H along the railway. I 7 It will be plaimtherefore, that I have provided a crossing signal which reproduces sound waves'created by a train approaching the crossing, and which for this reasonis very effective to warn users of the highway of the" approach of a train along the railway. Y i

which it is connected,

(ill

D operates 4 7 said highway,

'a train approaching the track intersected by a phone located in the some distance from said highway and ar- Although I have herein shown and described only one form of crossing signal embodying my invention, it is understood that various changes and modifications ma be madetherein. within the. scope ofthe appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

]1. In combination, astretch of railway track intersected by a highway, a microphone arranged to be vibrated by a train approaching said highway, and a loud speaker located adjacent the intersection ofsaidhighwa'y and said stretch and responsive to vibration of said microphone. r r L 2. In combination, a'stretch of railway track intersected by a highway, an electroresponsive sound producing'device located adjacent the intersection of said stretch and and means located in the trackway and responsive to vibrations produced by highway for operating said electr c-responsive device. 1

8; In combination, a stretch of railway track intersected by a highway, an electroresponsive sound producing device located adjacent the intersection of said stretch and said highway, a transformer having its secondary connected with said device, means for supplying the primary of said transformer with current, and means located in the trackway for varying the current suppliedto said primary in response to vibrations produced by a train approaching the highway.

In combination, a stretch of railway highway, an electro-' responsive sound producing device located acent the intersection of said highway and saidstretch, and means for supplying said device with current which is varied in response to vibration produced by a-train approaching the highwa 5. In combination, a stretch of railway track intersected by a highway, a loud speakor located adjacent the intersection of said stretch and said highway, and means located inthe trackway and responsiveto'vibrations producedby a train approaching the highway for operatingsaid loud speaker.

In combination, a stretch of railway track intersected by a highway, a microtrackway at a point ranged to be vibrated by a train approaching the highway, a circuit for said microphone, and a loud speaker receiving energy from said circuit and located at the intersection of said highway and said stretch for warning users of the highway of a train along the railway.

7. In combination, a stretch of railway the approach of track intersected by a highway, a loudspeaker located adjacent the intersection of said highway and said stretch, a transformer V duced V which caused the having its secondary connected with said loud speaker, a microphone located inthe trackway and subjectedto vibrations proby a train approaching the highway, and means controlled by said microphone for supplying the primary of said transformer with current.

' 8. In combination with a stretch of rail- Way track, a loud speaker, a transformer having its secondary-connected with said loud speaker, a source of electromotive force, a microphone clamped to a track rail of said stretch, and a circuit for said microphone including said source of electromotive force and the primary of said transformer.

9. In combination with a stretch of railway track, aloud speaker, a device located in. the trackway and arranged to vary its electrical resistance in response to vibration produced by a train moving along the trackway, and means for supplying said loud speaker with current which is varied in response to the variation in electrical resistance of said device. a

10. In combination with a stretch of railway track,'a microphone in the trackway provided with "an electrical circuit and arranged to vary the current in said circuit in response to sound waves produced by a train moving along speaker receiving energy from said circuit for faithfully reproducing the sound waves microphone to vary the current in said circuit.

11. In combination, a stretch of railway track intersected by a'highway, a rigid bar, means for clamping said bar transversely to the flange of one rail of said stretch at a point remote from said crossing, an insulating housing attached to said bar, a microphone in said'housing, and a loud speaker located adjacent said crossing and controlled by said microphone.

12. In combination, a stretch track intersected by a. highway, a microphone attached to a track rail so as to be vibrated by a train approaching the highway, and a signal'for said highway controlled by said microphone.

13. In combination, a stretch of railway track intersected by a highway, a highway signal located at said intersection, a micro phone attached'to a track rail, and means for causing operation of said signal when said microphone is vibrated by a train approaching the highway.

In testimony whereof I afiix my signature.

CONRAD H. ZIERDT.

of railway said stretch, and a loud 

